The first step is to stick our craft sticks together using sellotape or similar.  (the sticky plastic used for covering books is also good and can be cut to size).  Stick them in the order you want them to be arranged in the puzzle. I

Then you will start drawing your puzzle picture on the collection of sticks. The Cubs may want to use a combination of markers, crayons, and paint on your puzzles. You could also easily just pick one drawing tool to work with.  

Once dry, you need to peel the craft sticks off of the contact paper/sellotape.

Now you are ready to have someone try to put your puzzle together. There were so many blue and yellow sticks that had similar lines on them. One way you could make it easier would be to put numbers on the back of each stick.

See http://jdaniel4smom.com/2015/06/minion-craft-sticks-puzzle.html for original idea.

It doesn't have to be a single minion picture, can be an arrangement of minions.

Can be used for other themes as well: